This invention relates to door positioning means, and in particular to means to bias a door to the closed position and releasably retain it in that position. In one form of the invention the door positioning means can also bias a partly open door to the fully open position.
The principal function of the present invention is to act as a door closer. Many, forms of door closers have been devised in the past and some also retain a door in an open or part open condition as well as exerting a door closing force.
One form of such closer links the door to a door surround and includes means to bias the door to the closed condition and hold it in an open position. Such A closers rely on pneumatics or hydraulics for their operation and only allow approximately 90 degree door opening in a single direction. Besides the drawback of limiting the door opening to 90 degrees, hydraulic closers are reasonably complex and therefore expensive.
Door closers of the single and double spring type have been developed for 90 degree and 180 degree door opening actions. This form of closer is noisy in action and is subject to spring fatigue. The action of this form of closer is severe and can be dangerous to elderly persons and children. In addition, this form of closer does not incorporate a door hold-open capability.
A cam form of hinge has been developed for doors required to move through 180 degrees and be held in the closed and both fully open conditions. This form of hinge also biases the door to the closed position when the door is moved from the open position. This form of hinge involves vertical movement of the door during the door swinging action and is therefore limited in its application.
There is thus a need for a door positioning means which can work with doors intended for 90 degree and 180 degree opening and which can bias a door to a closed condition and hold the door in closed and not be limited in operation by the manners of operation of known door closers and positioning means. In a preferred arrangement the door positioning means would also be able to position a door in a partly open or fully open position.
Broadly stated, the present invention provides a door positioning means to releasably retain a hinged door in a closed position and bias a part open door from the part open position towards a closed or fully open position dependent upon the degree to which said door is open, said positioning means includes a first member for stationary mounting in juxtaposition to the top or the bottom of a door and having a magnet array disposed along a path which when said first member is mounted will be substantially concentric with the axis of hinging of said door, said magnet array including a first polarity first magnet means corresponding with a door closed position and an opposite polarity second magnet means spaced from the first magnet means along said path by a distance less than that traversed by the door in moving between the closed and fully open positions, a second member also having said opposite polarity for mounting on the door at a distance from the axis of pivoting of the door such that said second member will traverse said curved path, said first and second members in use having a spacing there between such that attraction and repulsion forces will develop between the second member and the first and second magnet means.